A superuser should use the -f option only if the executable to be examined is known to be trustworthy. The use of -f on an untrustworthy executable while superuser can compromise system security. If an executables trustworthyness is unknown, a superuser should temporarily become a regular user. Then invoke ldd as this regular user.

If you google it you can find this issue several times in the first few pages.

If you CHECK THE DOCUMENTATION for ldd, this issue is mentioned. Granted you have to read through a bunch first. But it is very clearly documented.